In proteome analysis, which bears a central position in post-genomic research, a combination of two-dimensional electrophoresis (2DE) and Western blotting has been known as an excellent separation analytical method. 2DE can separate proteomes with high resolution into a plurality of components (proteins), based on two independent physical properties unique to proteins (electric charge and molecular weight) using various separation media. In the case of further analyzing proteins using the separation results by 2DE, it is preferable to fixate the plurality of proteins contained in the separation medium on a transfer membrane by way of the Western blotting. This is because analysis is easy, since the proteins fixed to the transfer membrane can be stably kept over a long period. In particular, in the case of comprehensively comparing and reviewing a plurality of biological properties of proteins like the fluctuations in expression of proteins and existence of post-translational modification using the separation results by 2DE, Western blotting is considered an essential process.
In conventional Western blotting, there is a problem in that the patterns of proteins fixed to the transfer membrane blurs and warps due to bubbles generating from the anode adhering at the contact location between the transfer membrane and separation medium. To address this problem, Patent Document 1 discloses a scheme using a columnar anode coated with a porous material. Patent Document 1 discloses the advantage of this scheme as follows. Upon bubbles generating from the anode passing through the porous material, since the sizes thereof become large, the bubbles tend to rise to the water surface. Since it is thereby possible to prevent mixing of microscopic bubbles into the buffer, the negative influence of bubbles on the contact location can be eliminated.
Patent Document 1: U.S. Pat. No. 5,916,429 (issued Jun. 29, 1999)
Patent Document 2: U.S. Pat. No. 5,234,559 (issued Aug. 10, 1993)
Patent Document 3: Japanese Published Translation of PCT International Publication for Patent Applications “Japanese Unexamined Patent Application (Translation of PCT Publication), Publication No. H9-501774 (published Feb. 18, 1997)”